The present invention relates to systems and methods for monitoring and modifying behavior of a subject such as a human or an animal.
Successful dieting requires long-term behavior modification in terms of eating and physical activity. A diet plan is only part of the solution. Sticking to the plan requires behavior modification that is generally beyond the ability of most people to implement without external assistance. There does not appear to be a diet or process by which people can reliably lose weight and keep it off. Numerous studies have shown 100% weight regain on most diets. Other meta-studies show that people regain approximately 75% of the initial weight loss after five years.
Assessing energy balance, i.e. the net difference between energy intake and expenditure is central to obesity research, prevention, and treatment. The importance of accurately measuring energy balance is appreciated by considering the dynamics of average weight gain in middle aged adults which is about 10 lbs. per decade. This significant gain in weight follows from a net intake excess of approximately 0.3% of the daily calorie consumption, which is below the awareness of most individuals. [National Institutes of Health, Bioengineering Approaches To Energy Balance And Obesity (SBIR/STTR). http://grants1.nih.gov/grants/guide/pa-files/PA-04-156.html].
Today, energy intake is at best only crudely measured by self reporting food consumed, an approach that nutritionists know falls well short of its accuracy goals. Although standard self-report questionnaire and recall techniques can provide valuable data on dietary patterns, these techniques are time consuming, inconvenient, and infamous for considerable underreporting of food consumed, with this error more pronounced for over weight than non-over weight individuals.
Several devices and methods which attempt to overcome the deficiencies of self reporting approaches have been described in the prior art.
U.S. Pat. No. 6,135,950 describes a pager size device to aid in controlling a person's daily food intake. U.S. Pat. No. 5,398,688 describes a timer for calculating and alerting a user when their maximum eating time has expired. U.S. Pat. Nos. 5,188,104 and 5,263,480 describe the treatment of eating disorders by nerve stimulation by detecting preselected events indicative of imminent need for treatment and applying predetermined stimulating signal to patient vagus nerve. PCT Publication WO 02/053093 and U.S. application Publication No. 2004/0147816, describe a similar invasive technique except that the stimulation is driven into the stomach muscle of the subject, thereby altering the timing of digestion. PCT Publication No. WO 02/026101, describes a generic arrangement of implantable sensors, microprocessors and a negative-feedback stimulator which can enforce a corrective regimen on a patient suffering from a dietary or other behavioral disorder.
Unfortunately none of the approaches described above have been shown to be effective. The only non-drug interventions for losing weight that display some long-term efficacy are the various procedures to reduce the volume of the stomach or bypass it altogether so that just a small volume of food may satiate the patient. While such approaches show some promise, they require invasive surgical procedures with attendant risks and pain, they often require permanent prosthetic implants and/or irreversible modification of the patient's digestive tract with potentially serious complications and side effects, they are costly, and they require long recovery time during which the patient is immobile and unproductive. Many of those who are overweight or obese are thus unable or unwilling to undergo such interventions.
There is thus a widely recognized need for, and it would be highly advantageous to have, a system and method for controlling eating behavior without the invasiveness, risks, pain, complications, cost, and recovery time associated with stomach volume reduction and bypass procedures.